/**
 * Bank statement extraction using MiniCPM-V (visual extraction)
 *
 * JSON per-page approach with streaming output:
 * 1. Ask for structured JSON of all transactions per page
 * 2. Single pass extraction (no consensus)
 */
import { tap, expect } from '@git.zone/tstest/tapbundle';
import * as fs from 'fs';
import * as path from 'path';
import { execSync } from 'child_process';
import * as os from 'os';
import { ensureMiniCpm } from './helpers/docker.js';

const OLLAMA_URL = 'http://localhost:11434';
const MODEL = 'openbmb/minicpm-v4.5:q8_0';

interface ITransaction {
  date: string;
  counterparty: string;
  amount: number;
}

const JSON_PROMPT = `Extract ALL transactions from this bank statement page as a JSON array.

IMPORTANT RULES:
1. Each transaction has: date, description/counterparty, and an amount
2. Amount is NEGATIVE for money going OUT (debits, payments, withdrawals)
3. Amount is POSITIVE for money coming IN (credits, deposits, refunds)
4. Date format: YYYY-MM-DD
5. Do NOT include: opening balance, closing balance, subtotals, headers, or summary rows
6. Only include actual transactions with a specific date and amount

Return ONLY this JSON format, no explanation:
[
  {"date": "2021-06-01", "counterparty": "COMPANY NAME", "amount": -25.99},
  {"date": "2021-06-02", "counterparty": "DEPOSIT FROM", "amount": 100.00}
]`;

/**
 * Convert PDF to PNG images using ImageMagick
 */
function convertPdfToImages(pdfPath: string): string[] {
  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'pdf-convert-'));
  const outputPattern = path.join(tempDir, 'page-%d.png');

  try {
    execSync(
      `convert -density 300 -quality 100 "${pdfPath}" -background white -alpha remove "${outputPattern}"`,
      { stdio: 'pipe' }
    );

    const files = fs.readdirSync(tempDir).filter((f: string) => f.endsWith('.png')).sort();
    const images: string[] = [];

    for (const file of files) {
      const imagePath = path.join(tempDir, file);
      const imageData = fs.readFileSync(imagePath);
      images.push(imageData.toString('base64'));
    }

    return images;
  } finally {
    fs.rmSync(tempDir, { recursive: true, force: true });
  }
}

/**
 * Query for JSON extraction with streaming output
 */
async function queryJson(image: string, queryId: string): Promise<string> {
  const startTime = Date.now();
  process.stdout.write(`      [${queryId}] `);

  const response = await fetch(`${OLLAMA_URL}/api/chat`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      model: MODEL,
      messages: [{
        role: 'user',
        content: JSON_PROMPT,
        images: [image],
      }],
      stream: true,
      options: {
        num_ctx: 32768,
        num_predict: 4000,
        temperature: 0.1,
      },
    }),
  });

  if (!response.ok) {
    const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
    process.stdout.write(`ERROR: ${response.status} (${elapsed}s)\n`);
    throw new Error(`Ollama API error: ${response.status}`);
  }

  let content = '';
  const reader = response.body!.getReader();
  const decoder = new TextDecoder();

  try {
    while (true) {
      const { done, value } = await reader.read();
      if (done) break;

      const chunk = decoder.decode(value, { stream: true });
      for (const line of chunk.split('\n').filter(l => l.trim())) {
        try {
          const json = JSON.parse(line);
          const token = json.message?.content || '';
          if (token) {
            process.stdout.write(token);
            content += token;
          }
        } catch {
          // Ignore parse errors for partial chunks
        }
      }
    }
  } finally {
    const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
    process.stdout.write(` (${elapsed}s)\n`);
  }

  return content.trim();
}

/**
 * Sanitize JSON string - fix common issues from vision model output
 */
function sanitizeJson(jsonStr: string): string {
  let s = jsonStr;

  // Fix +number (e.g., +93.80 -> 93.80) - JSON doesn't allow + prefix
  // Handle various whitespace patterns
  s = s.replace(/"amount"\s*:\s*\+/g, '"amount": ');
  s = s.replace(/:\s*\+(\d)/g, ': $1');

  // Fix European number format with thousands separator (e.g., 1.000.00 -> 1000.00)
  // Pattern: "amount": X.XXX.XX where X.XXX is thousands and .XX is decimal
  s = s.replace(/"amount"\s*:\s*(-?)(\d{1,3})\.(\d{3})\.(\d{2})\b/g, '"amount": $1$2$3.$4');
  // Also handle larger numbers like 10.000.00
  s = s.replace(/"amount"\s*:\s*(-?)(\d{1,3})\.(\d{3})\.(\d{3})\.(\d{2})\b/g, '"amount": $1$2$3$4.$5');

  // Fix trailing commas before ] or }
  s = s.replace(/,\s*([}\]])/g, '$1');

  // Fix unescaped newlines inside strings (replace with space)
  s = s.replace(/"([^"\\]*)\n([^"]*)"/g, '"$1 $2"');

  // Fix unescaped tabs inside strings
  s = s.replace(/"([^"\\]*)\t([^"]*)"/g, '"$1 $2"');

  // Fix unescaped backslashes (but not already escaped ones)
  s = s.replace(/\\(?!["\\/bfnrtu])/g, '\\\\');

  // Fix common issues with counterparty names containing special chars
  s = s.replace(/"counterparty":\s*"([^"]*)'([^"]*)"/g, '"counterparty": "$1$2"');

  // Remove control characters except newlines (which we handle above)
  s = s.replace(/[\x00-\x08\x0B\x0C\x0E-\x1F]/g, ' ');

  return s;
}

/**
 * Parse JSON response into transactions
 */
function parseJsonResponse(response: string, queryId: string): ITransaction[] {
  console.log(`      [${queryId}] Parsing response...`);

  // Try to find JSON in markdown code block
  const codeBlockMatch = response.match(/```(?:json)?\s*([\s\S]*?)```/);
  let jsonStr = codeBlockMatch ? codeBlockMatch[1].trim() : response.trim();

  if (codeBlockMatch) {
    console.log(`      [${queryId}] Found JSON in code block`);
  }

  // Sanitize JSON (fix +number issue)
  jsonStr = sanitizeJson(jsonStr);

  try {
    const parsed = JSON.parse(jsonStr);
    if (Array.isArray(parsed)) {
      const txs = parsed.map(tx => ({
        date: String(tx.date || ''),
        counterparty: String(tx.counterparty || tx.description || ''),
        amount: parseAmount(tx.amount),
      }));
      console.log(`      [${queryId}] Parsed ${txs.length} transactions (direct)`);
      return txs;
    }
    console.log(`      [${queryId}] Parsed JSON is not an array`);
  } catch (e) {
    const errMsg = (e as Error).message;
    console.log(`      [${queryId}] Direct parse failed: ${errMsg}`);

    // Log problematic section with context
    const posMatch = errMsg.match(/position (\d+)/);
    if (posMatch) {
      const pos = parseInt(posMatch[1]);
      const start = Math.max(0, pos - 40);
      const end = Math.min(jsonStr.length, pos + 40);
      const context = jsonStr.substring(start, end);
      const marker = ' '.repeat(pos - start) + '^';
      console.log(`      [${queryId}] Context around error position ${pos}:`);
      console.log(`      [${queryId}] ...${context}...`);
      console.log(`      [${queryId}]    ${marker}`);
    }

    // Try to find JSON array pattern
    const arrayMatch = jsonStr.match(/\[[\s\S]*\]/);
    if (arrayMatch) {
      console.log(`      [${queryId}] Found array pattern, trying to parse...`);
      const sanitizedArray = sanitizeJson(arrayMatch[0]);
      try {
        const parsed = JSON.parse(sanitizedArray);
        if (Array.isArray(parsed)) {
          const txs = parsed.map(tx => ({
            date: String(tx.date || ''),
            counterparty: String(tx.counterparty || tx.description || ''),
            amount: parseAmount(tx.amount),
          }));
          console.log(`      [${queryId}] Parsed ${txs.length} transactions (array match)`);
          return txs;
        }
      } catch (e2) {
        const errMsg2 = (e2 as Error).message;
        console.log(`      [${queryId}] Array parse failed: ${errMsg2}`);
        const posMatch2 = errMsg2.match(/position (\d+)/);
        if (posMatch2) {
          const pos2 = parseInt(posMatch2[1]);
          console.log(`      [${queryId}] Context around error: ...${sanitizedArray.substring(Math.max(0, pos2 - 30), pos2 + 30)}...`);
        }

        // Try to extract individual objects from the malformed array
        console.log(`      [${queryId}] Attempting object-by-object extraction...`);
        const extracted = extractTransactionsFromMalformedJson(sanitizedArray, queryId);
        if (extracted.length > 0) {
          console.log(`      [${queryId}] Recovered ${extracted.length} transactions via object extraction`);
          return extracted;
        }
      }
    } else {
      console.log(`      [${queryId}] No array pattern found in response`);
      console.log(`      [${queryId}] Raw response preview: ${response.substring(0, 200)}...`);
    }
  }

  console.log(`      [${queryId}] PARSE FAILED - returning empty array`);
  return [];
}

/**
 * Extract transactions from malformed JSON by parsing objects individually
 */
function extractTransactionsFromMalformedJson(jsonStr: string, queryId: string): ITransaction[] {
  const transactions: ITransaction[] = [];

  // Match individual transaction objects
  const objectPattern = /\{\s*"date"\s*:\s*"([^"]+)"\s*,\s*"counterparty"\s*:\s*"([^"]+)"\s*,\s*"amount"\s*:\s*([+-]?\d+\.?\d*)\s*\}/g;
  let match;

  while ((match = objectPattern.exec(jsonStr)) !== null) {
    transactions.push({
      date: match[1],
      counterparty: match[2],
      amount: parseFloat(match[3]),
    });
  }

  // Also try with different field orders (amount before counterparty, etc.)
  if (transactions.length === 0) {
    const altPattern = /\{\s*"date"\s*:\s*"([^"]+)"[^}]*"amount"\s*:\s*([+-]?\d+\.?\d*)[^}]*\}/g;
    while ((match = altPattern.exec(jsonStr)) !== null) {
      // Try to extract counterparty from the match
      const counterpartyMatch = match[0].match(/"counterparty"\s*:\s*"([^"]+)"/);
      const descMatch = match[0].match(/"description"\s*:\s*"([^"]+)"/);
      transactions.push({
        date: match[1],
        counterparty: counterpartyMatch?.[1] || descMatch?.[1] || 'UNKNOWN',
        amount: parseFloat(match[2]),
      });
    }
  }

  return transactions;
}

/**
 * Parse amount from various formats
 */
function parseAmount(value: unknown): number {
  if (typeof value === 'number') return value;
  if (typeof value !== 'string') return 0;

  let s = value.replace(/[€$£\s]/g, '').replace('−', '-').replace('–', '-');
  // European format: comma is decimal
  if (s.includes(',') && s.indexOf(',') > s.lastIndexOf('.')) {
    s = s.replace(/\./g, '').replace(',', '.');
  } else {
    s = s.replace(/,/g, '');
  }
  return parseFloat(s) || 0;
}

/**
 * Extract transactions from a single page (single pass)
 */
async function extractTransactionsFromPage(image: string, pageNum: number): Promise<ITransaction[]> {
  console.log(`\n    ======== Page ${pageNum} ========`);

  const queryId = `P${pageNum}`;
  const response = await queryJson(image, queryId);
  const transactions = parseJsonResponse(response, queryId);

  console.log(`    [Page ${pageNum}] Extracted ${transactions.length} transactions:`);
  for (let i = 0; i < transactions.length; i++) {
    const tx = transactions[i];
    console.log(`      ${(i + 1).toString().padStart(2)}. ${tx.date} | ${tx.counterparty.substring(0, 30).padEnd(30)} | ${tx.amount >= 0 ? '+' : ''}${tx.amount.toFixed(2)}`);
  }

  return transactions;
}

/**
 * Extract all transactions from bank statement
 */
async function extractTransactions(images: string[]): Promise<ITransaction[]> {
  console.log(`    [Vision] Processing ${images.length} page(s) with ${MODEL} (single pass)`);

  const allTransactions: ITransaction[] = [];

  for (let i = 0; i < images.length; i++) {
    const pageTransactions = await extractTransactionsFromPage(images[i], i + 1);
    allTransactions.push(...pageTransactions);
  }

  console.log(`    [Vision] Total: ${allTransactions.length} transactions`);
  return allTransactions;
}

/**
 * Compare extracted transactions against expected
 */
function compareTransactions(
  extracted: ITransaction[],
  expected: ITransaction[]
): { matches: number; total: number; errors: string[]; variations: string[] } {
  const errors: string[] = [];
  const variations: string[] = [];
  let matches = 0;

  for (let i = 0; i < expected.length; i++) {
    const exp = expected[i];
    const ext = extracted[i];

    if (!ext) {
      errors.push(`Missing transaction ${i}: ${exp.date} ${exp.counterparty}`);
      continue;
    }

    const dateMatch = ext.date === exp.date;
    const amountMatch = Math.abs(ext.amount - exp.amount) < 0.01;

    if (dateMatch && amountMatch) {
      matches++;
      // Track counterparty variations (date and amount match but name differs)
      if (ext.counterparty !== exp.counterparty) {
        variations.push(
          `[${i}] "${exp.counterparty}" → "${ext.counterparty}"`
        );
      }
    } else {
      errors.push(
        `Mismatch at ${i}: expected ${exp.date}/${exp.amount}, got ${ext.date}/${ext.amount}`
      );
    }
  }

  if (extracted.length > expected.length) {
    errors.push(`Extra transactions: ${extracted.length - expected.length}`);
  }

  return { matches, total: expected.length, errors, variations };
}

/**
 * Find all test cases (PDF + JSON pairs) in .nogit/
 */
function findTestCases(): Array<{ name: string; pdfPath: string; jsonPath: string }> {
  const testDir = path.join(process.cwd(), '.nogit');
  if (!fs.existsSync(testDir)) {
    return [];
  }

  const files = fs.readdirSync(testDir);
  const pdfFiles = files.filter((f: string) => f.endsWith('.pdf'));
  const testCases: Array<{ name: string; pdfPath: string; jsonPath: string }> = [];

  for (const pdf of pdfFiles) {
    const baseName = pdf.replace('.pdf', '');
    const jsonFile = `${baseName}.json`;
    if (files.includes(jsonFile)) {
      testCases.push({
        name: baseName,
        pdfPath: path.join(testDir, pdf),
        jsonPath: path.join(testDir, jsonFile),
      });
    }
  }

  return testCases.sort((a, b) => a.name.localeCompare(b.name));
}

// Tests

tap.test('setup: ensure Docker containers are running', async () => {
  console.log('\n[Setup] Checking Docker containers...\n');
  const minicpmOk = await ensureMiniCpm();
  expect(minicpmOk).toBeTrue();
  console.log('\n[Setup] All containers ready!\n');
});

tap.test('should have MiniCPM-V model loaded', async () => {
  const response = await fetch(`${OLLAMA_URL}/api/tags`);
  const data = await response.json();
  const modelNames = data.models.map((m: { name: string }) => m.name);
  expect(modelNames.some((name: string) => name.includes('minicpm'))).toBeTrue();
});

const testCases = findTestCases();
console.log(`\nFound ${testCases.length} bank statement test cases (MiniCPM-V)\n`);

let passedCount = 0;
let failedCount = 0;

for (const testCase of testCases) {
  tap.test(`should extract: ${testCase.name}`, async () => {
    const expected: ITransaction[] = JSON.parse(fs.readFileSync(testCase.jsonPath, 'utf-8'));
    console.log(`\n=== ${testCase.name} ===`);
    console.log(`Expected: ${expected.length} transactions`);

    const images = convertPdfToImages(testCase.pdfPath);
    console.log(`  Pages: ${images.length}`);

    const extracted = await extractTransactions(images);
    console.log(`  Extracted: ${extracted.length} transactions`);

    const result = compareTransactions(extracted, expected);
    const perfectMatch = result.matches === result.total && extracted.length === expected.length;

    if (perfectMatch) {
      passedCount++;
      console.log(`  Result: PASS (${result.matches}/${result.total})`);
    } else {
      failedCount++;
      console.log(`  Result: FAIL (${result.matches}/${result.total})`);
      result.errors.slice(0, 10).forEach((e) => console.log(`    - ${e}`));
    }

    // Log counterparty variations (names that differ but date/amount matched)
    if (result.variations.length > 0) {
      console.log(`  Counterparty variations (${result.variations.length}):`);
      result.variations.forEach((v) => console.log(`    ${v}`));
    }

    expect(result.matches).toEqual(result.total);
    expect(extracted.length).toEqual(expected.length);
  });
}

tap.test('summary', async () => {
  const total = testCases.length;
  console.log(`\n======================================================`);
  console.log(`   Bank Statement Summary (${MODEL})`);
  console.log(`======================================================`);
  console.log(`  Method:   JSON per-page (single pass)`);
  console.log(`  Passed:   ${passedCount}/${total}`);
  console.log(`  Failed:   ${failedCount}/${total}`);
  console.log(`======================================================\n`);
});

export default tap.start();